1. Field of the Invention
This invention relates to a supporting device.
2. Description of the Prior Art
In supporting electrical cables in the electrical systems of ships, in underground electrical lines, underground telephone lines, and the like, it is customary to provide brackets attached to supports, with the cables resting on the brackets. These bracket and support assemblies have left much to be desired in that they are ordinarily relatively expensive to manufacture and install, may be awkward and difficult to use in supporting the cables and may be vulnerable to failure from the loads encountered, both static and dynamic. It may be necessary to have access to the area in back of the support when the attachment is made, which means that a clearance must be provided. This adds to the overall size of the support and bracket assembly, which is especially undesirable in underground installations and other places where space is limited.
A major improvement is represented by our earlier invention set forth in U.S. Pat. No. 3,923,277, which provides a cantilevered bracket of much greater load resistance than earlier designs. Attachment of the bracket to a support, such as a square tube, is accomplished by extending a bolt or other fastener through an opening in the vertical portion of the bracket, after which the threading of a nut onto the bolt or stud completes the attachment.
Although the advantages of this bracket are significant, it nevertheless requires the time-consuming operation of threading the nut onto the bolt or stud in accomplishing the attachment of the bracket to its support. The existence of a threaded connection inevitably raises the possibility of loosening from vibrational loads. The bolt or stud, with its associated nut and washer, represents a substantial expense in a system that utilizes a multiplicity of the brackets. Some past designs have done away with a separate fastener for the bracket, but these have lacked strength and reliability, and in some cases are relatively complex and hard to use. Hence, there has been a need for a bracket support which is strong and thoroughly reliable, yet which is more economical to manufacture and use than those heretofore available.